如何在viewDidLoad之后創建/添加UIView？

Question

我試圖在收到網絡請求的響應后創建按鈕。 在加載視圖后，如何在創建它們之后進行定位。 我還以編程方式創建我的視圖並使用AutoLayout。

CustomView.swift

class CustomView: UIView {

    override init(frame: CGRect) {
        super.init(frame: UIScreen.main.bounds)
        backgroundColor = .red
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

}

ViewController.swift

// Load custom view
override func loadView() {
    view = CustomView()
}

override func viewDidLoad() {
    super.viewDidLoad()

    // Create buttons after getting response
    viewModel.output.apiOutput
        .subscribe(onNext: { posts in
            for post in posts {
                // create buttons
            }
        })
        .dispose(by: disposeBag)

}

Answer 1

嘗試將按鈕添加到viewWillAppear（）的覆蓋

https://developer.apple.com/documentation/uikit/uiviewcontroller/1621510-viewwillappear

或者這個較舊的帖子可能會幫助你：

如何以編程方式創建按鈕？

但我會首先嘗試使用viewWillAppear（）

Answer 2

/// Helper function to create a new button.
func createButton(_ title: String) -> UIButton {
    let button = UIButton()
    button.backgroundColor = .blue
    button.setTitle(title, .normal)

    // Add the button as a subview.
    self.view.addSubview(button)
}

override func viewDidLoad() {
    super.viewDidLoad()

    // Just set the viewController's view to your custom view here.
    self.view = CustomView()

    // Create buttons after getting response
    viewModel.output.apiOutput
        .subscribe(onNext: { posts in
            for post in posts {
                // Create a button. Change "title" to the title of your post, etc.
                let button = createButton("Title")
                // Constrain your button here!
            }
        })
        .dispose(by: disposeBag)
}

在哪里說// Constrain your button here! - 如果你想在一行或一列中有多個按鈕，我建議使用UIStackView，並將它們添加為ArrangedSubviews。